The systematic IUPAC nomenclature of ethers (molecules of the structure ) is such that the smaller of the two alkyl groups is labeled as an "alkoxy" substituent of the larger chain. In the molecule shown, the longer chain has  carbons and does not contain any multiple bonds or functional groups. Therefore the parent chain is "." The ether functionality is thus called a "" group (a carbon chain one carbon long, "" attached to an oxygen "" which is attached to the parent chain by said oxygen), and is a substituent of the parent chain. Since there are multiple places the  group can attache to the parent chain, a locand must be specified in this case (thus "."

The carbon chain is four carbons long (thus ""), and the presence of a double bond makes it an alkene (thus ""). Numbering the carbon chain from left to right puts the double bond between carbons  and , while numbering from right to left puts the double bond between carbons  and . Because the alkene is the most important functionality in this molecule, the carbon chain is numbered such that the double bond gets the lower numbers (thus, the carbon chain is numbered from right to left). Because there are multiple possible positions of the double bond it is necessary to put a locand on the lower numbered carbon that is involved in the double bond. In this case, it would be called "."

The longest carbon chain is  carbons long (thus ""), and the lack of a double bond makes it an alkane (thus ""). The carbon chain must be numbered giving the substituents the lower numbers. Counting from right to left puts the bromine and methyl groups on carbons  and  respectively, which is lower than the designations counting from left to right ; therefore, the numbering goes from right to left. IUPAC rules state that the substituents are listed in alphabetical order when naming (thus ")."

When naming an organic compound by the IUPAC, it's best to first start by identifying the functional groups present.

We have an amide shown here:

We have an ethyl group shown here:

and Finally we have an alcohol (hydroxy) group shown here:

Next, we should identify what functional group has the highest priority, as that will form the base name of the compound:

According to IUPAC convention, Carboxylic Acid derivatives including Amides have the highest priority then carbonyls then alcohols, amines, alkenes, alkynes, and alkanes, so in this case the Amide group has the highest priority and therefore makes up the name of the base compound.

Next, we want to number the longest carbon chain with the highest priority functional group with the lowest number. In this case this means we want the carbonyl of the amide to be carbon number #1, so let's start there and number the carbon chain.

You should get something like this:

Now that we have numbered the carbon chain we can begin our naming.

Let's start with the base name:

According to IUPAC convention the base name for an amide compound is -amide, so in this case we have a hexanamide, which can also be written as hexan-1-amide, but this isn't needed as it as the amide is at carbon 1.

Next we have an ethyl group at carbon 4, which gives us:

4-ethylhexanamide.

Finally we have an alcohol group at carbon 5, which as a substituent is referred to as an hydroxy.

so we have a 5-hydroxy group.

Now we must order the substituents in alphabetical order to follow IUPAC rules, so our final answer is 4-ethyl-5-hydroxyhexanamide.

Now let's go over the wrong answer choices:

1) 6-carboxamide-3-ethylhexan-2-ol is wrong because it interprets the amide as being lower priority than the alcohol.

2) 4-ethyl-5-hydroxypentanamide is incorrect because the longest carbon chain is six carbons long, not 5.

3) 3-ethyl-2-hydroxyhexan-6-amide is wrong because the amide group isn't the lowest number it can possibly be, as according to IUPAC rules the highest priority functional group should have the lowest possible numbering.

4) 3-ethyl-2-hydroxypentan-5-amide is wrong because the amide isn't the lowest number it can be and the longest carbon chain is 6 carbons, not 5.

When naming an organic compound by the IUPAC, it's best to first start by identifying the functional groups present.

In this particular case we have:

An amide shown here:

A Bromine (bromo) group shown here:

A Fluorine (fluoro) group shown here:

and A chlorine (chloro) group shown here:

Next, we should identify what functional group has the highest priority, as that will form the base name of the compound:

According to IUPAC convention, Carboxylic Acid derivatives including amides have the highest priority then carbonyls then alcohols, amines, alkenes, alkynes, and alkanes, so in this case the amide group has the highest priority and therefore makes up the name of the base compound.

Next, we want to number the longest carbon chain with the highest priority functional group with the lowest number. In this case this means we want the carbon on the ring that the amide is attached to to be #1, so let's start there and number the carbon chain, and then we go in alphabetical order for the substituents, so we make bromo a lower number than chloro.

You should get something like this:

Now that we have numbered the carbon chain we can begin our naming.

Let's start with the base name:

Since this is a cyclic compound we name the compound cyclohexanecarboxamide, as in IUPAC nomenclature you name the ring normally then put carboxamide at the end to show it has an amide attached to it.

Next we number the substituent alkyl halides so that they are in alphabetically order and the one that is nearest to the beginning of the alphabet has the lowest priority, so we have a 3-bromo, 4-fluoro, and 5-chloro.

Putting this together and ordering the substituents named in alphabetical order, we get 3-bromo-5-chloro-4-fluorocyclohexanecarboxamide as our final answer.

Now let's go over the wrong answers:

1) 3-bromo-5-chloro-4-fluorocyclohexanamide is wrong because in IUPAC nomenclature we must name the ring normally and then put carboxamide after it.

2) 3-bromo-5-chloro-4-fluorohexanamide is wrong because it ignores the fact that this compound is cyclic (a ring), and would be the correct name if this were a straight chain compound.

3) 5-bromo-3-chloro-4-fluorocyclohexanecarboxamide is wrong because the substituents aren't numbered in alphabetical order so that the lowest number alkyl halide is closest to the beginning of the alphabet.

4) 5-bromo-3-chloro-4-fluorocyclohexanamide is wrong because the substituents aren't numbered in alphabetical order so that the lowest number alkyl halide is closest to the beginning of the alphabet. It is also wrong because in IUPAC nomenclature we must name the ring normally and then put carboxamide after it.

When naming an organic compound by the IUPAC, it's best to first start by identifying the functional groups present.

In this particular case we have:

An acyl chloride:

An Alcohol (hydroxy) group:

and an Ethyl group:

Next, we should identify what functional group has the highest priority, as that will form the base name of the compound:

According to IUPAC convention, Carboxylic Acid derivatives including acyl halides have the highest priority then carbonyls then alcohols, amines, alkenes, alkynes, and alkanes, so in this case the Ester group has the highest priority and therefore makes up the name of the base compound.

Next, we want to number the longest carbon chain with the highest priority functional group with the lowest number. In this case this means we want the carbon on the ring attached to the acyl chloride to be carbon number #1, so let's start there and number the carbon chain.

You should get something like this:

Let's start with the base name:

According to IUPAC convention the base name for an acyl halide ring requires us to name the ring normally and then put carbonyl ____ide (where ___ is the name of the halogen) after it. In this case the base name becomes cyclopentanecarbonyl chloride.

Next we must try to make the next greatest priority group the lowest priority, which is the alcohol (hydroxy) group, and since this is next to carbon #1 it becomes carbon #2.

This means our name thus far for the compound is 2-hydroxycyclopentanecarbonyl chloride.

Finally we have an ethyl group at carbon #4, so it becomes 4-ethyl. Now we order our substituents named in alphabetical order so the final name is 4-ethyl-2-hydroxycyclopentanecarbonyl chloride.

Now let's look at the wrong answer choices:

1) 4-ethyl-2-hydroxycyclopentonyl chloride is wrong because according to IUPAC nomenclature cyclic acyl halides must be named normally with carbonyl ___ide (where ___ is the name of the halide) at the end of the name of the ring.

2) 4-ethyl-2-hydroxypentonyl chloride is wrong because the base name used is for the straight chain version of the compound when this compound is a ring.

3) 3-ethyl-5-hydroxypentonyl chloride is name because the hydroxy group is a higher priority than the ethyl substituent, so it needs to have a lower number if possible according to IUPAC rules. It is also wrong because the base name used is for the straight chain version of the compound when this compound is a ring.

4) 3-ethyl-5-hydroxycyclopentonyl chloride is wrong because the hydroxy group is a higher priority than the ethyl substituent, so it needs to have a lower number if possible according to IUPAC rules. It is also wrong because according to IUPAC nomenclature cyclic acyl halides must be named normally with carbonyl ___ide (where ___ is the name of the halide) at the end of the name of the ring.

When naming an organic compound by the IUPAC, it's best to first start by identifying the functional groups present.

In this particular case we have:

A Carboxylic Acid:

A Ketone:

An Alcohol (hydroxy) group:

Next, we should identify what functional group has the highest priority, as that will form the base name of the compound:

According to IUPAC convention, Carboxylic Acid and their derivatives have the highest priority then carbonyls then alcohols, amines, alkenes, alkynes, and alkanes, so in this case the Carboxylic acid group has the highest priority and therefore makes up the name of the base compound.

Next, we want to number the longest carbon chain with the highest priority functional group with the lowest number. In this case this means we want the carbon on the ring attached to the carboxylic acid to be carbon number #1, so let's start there and number the carbon chain.

You should get something like this:

Now that we have numbered the carbon chain we can begin our naming.

Let's start with the base name:

According to IUPAC convention the base name for an carboxylic acid ring requires us to name the ring normally and then put carboxylic acid after it. In this case the base name becomes cyclohexanecarboxylic acid.

The next highest priority group is the ketone next to the carbon #1, which is named as a substituent as it is lower priority than the carboxylic acid, so we have 2-oxocyclohexanecarboxylic acid.

Finally we have a hydroxy group at carbon 3, which is 3-hydroxy, so after ordering the substituents alphabetically we get the final answer of 3-hydroxy-2-oxocyclohexanecarboxylic acid.

Now let’s look at the wrong answers:

1) 3-hydroxy-2-oxocyclohexanoic acid is wrong because according to IUPAC nomenclature cyclic acids must be named normally with carboxylic acid at the end of the name of the ring.

2) 3-hydroxy-2-oxohexanoic acid is wrong because this is a ring, and that is the name given to the straight chain version of this compound.

3) 5-hydroxy-6-oxocyclohexanecarboxylic acid is wrong because it ignores the fact that the ketone group is a higher priority substituent than the alcohol, so it can be assigned to be on carbon 2 instead of 6.

4) 5-hydroxy-6-oxohexanoic acid is wrong because this is a ring, and that is the name given to the straight chain version of this compound. It is also wrong it ignores the fact that the ketone group is a higher priority substituent than the alcohol, so it can be assigned to be on carbon 2 instead of 6.

When naming an organic compound by the IUPAC, it's best to first start by identifying the functional groups present.

In this particular case we have:

An acyl chloride:

An alcohol:

and An amine:

Next, we should identify what functional group has the highest priority, as that will form the base name of the compound:

According to IUPAC convention, Carboxylic Acid derivatives including acyl halides (in the case the acyl chloride) have the highest priority then carbonyls then alcohols, amines, alkenes, alkynes, and alkanes, so in this case the acyl chloride group has the highest priority and therefore makes up the name of the base compound.

Next, we want to number the longest carbon chain with the highest priority functional group with the lowest number. In this case this means we want the carbonyl carbon on the acyl chloride to be carbon number #1 as it has the highest priority, so let's start there and number the carbon chain.

You should get something like this:

Let's start with the base name:

According to IUPAC naming conventions for straight chained acyl halides their names end with -oyl __halide (where __ is the name of the halide), so in this case we have -oyl chloride. Since this is a five carbon chain we have pentanoyl chloride as our base name.

Next, notice the next highest priority group is an alcohol substituent (hydroxy) group on carbon #3, so we have 3-hydroxypentanoyl chloride.

Finally we have an amine on carbon #4, so we name this substituent 4-amino, so after ordering the substituents alphabetically we get the final answer: 4-amino-3-hydroxypentanoyl chloride.

Now let’s look at the wrong answers:

1) 4-amino-3-hydroxypentenoyl chloride is wrong because it says pentenoyl instead of pentanoyl. Pentenoyl implies there is an alkene present and there isn't.

2) 2-amino-3-hydroxypentan-5-oyl chloride is wrong because it makes the amino group a higher priority and therefore lower number than the alcohol and acyl halide, when naming must be done according to the acyl halide as it is the highest priority group.

3) 4-amino-3-hydroxyhexanoyl chloride is wrong because it miscounts the number of carbons on the longest chain, which is 5, not 6.

4) 4-amino-3-hydroxybutanoyl chloride is wrong because it miscounts the number of carbons on the longest chain, which is 5, not 4.

When naming an organic compound by the IUPAC, it's best to first start by identifying the functional groups present.

In this particular case we have:

A carboxylic acid:

A methyl group:

and a methoxy ether group:

Next, we should identify what functional group has the highest priority, as that will form the base name of the compound:

According to IUPAC convention, Carboxylic Acids and their derivatives have the highest priority then carbonyls then alcohols, amines, alkenes, alkynes, and alkanes, so in this case the Carboxylic acid group has the highest priority and therefore makes up the name of the base compound.

Next, we want to number the longest carbon chain with the highest priority functional group with the lowest number. In this case this means we want the carbonyl carbon on the carboxylic acid to be carbon number #1 as it has the highest priority, so let's start there and number the carbon chain.

You should get something like this:

Now that we have numbered the carbon chain we can begin our naming.

Let's start with the base name:

According to IUPAC convention the base name for an carboxylic acid requires us to name the chain and then put __oic acid after it. In this case the base name becomes pentanoic acid.

Our next highest priority group is the ether (methoxy group), which is labeled as 4-methoxy and since the methyl group is directly between the methoxy and carboxylic acid group it becomes labeled as 3-methyl, as that is the only way to allow the carboxylic acid to be carbon #1.

Finally after ordering the substituents alphabetically we get the final answer of 4-methoxy-3-methylpentanoic acid, 

 which is our final answer. 

Now let’s look at the wrong answers:

1) 3-methyl-4-methoxypentanoic acid is wrong because according to IUPAC naming conventions the substituents must be organized in alphabetical order therefore 4-methoxy should be listed before 3-methyl in the name.

2) 2-methoxy-3-methylpentan-5-oic acid is wrong because the carboxylic acid, which is the highest priority should be assigned the lowest number, which is 1, not 5.

3) 2-methyl-3-methoxypentan-5-oic acid is wrong because because the carboxylic acid, which is the highest priority should be assigned the lowest number, which is 1, not 5. It is also wrong because according to IUPAC naming conventions the substituents must be organized in alphabetical order therefore 3-methoxy should be listed before 2-methyl in the name.

4) 1-hydroxy-4-methoxy-3-methylpentanone is wrong because it mistakes the carboxylic acid group as being an alcohol and a ketone and names them independently.

When naming an organic compound by the IUPAC, it's best to first start by identifying the functional groups present.

In this particular case we have:

An Amide:

3 Bromine (bromo) groups:

An Alcohol (Hydroxy) group:

Next, we should identify what functional group has the highest priority, as that will form the base name of the compound:

According to IUPAC convention, Carboxylic Acid derivatives including amides have the highest priority then carbonyls then alcohols, amines, alkenes, alkynes, and alkanes, so in this case the amide group has the highest priority and therefore makes up the name of the base compound.

Next, we want to number the longest carbon chain with the highest priority functional group with the lowest number. In this case this means we want the carbonyl carbon on the acyl chloride to be carbon number #1 as it has the highest priority, so let's start there and number the carbon chain.

You should get something like this:

Now that we have numbered the carbon chain we can begin our naming.

Let's start with the base name:

According to IUPAC convention the base name for an amide requires us to name the chain and then put __amide after it. In this case the base name becomes heptanamide.

We also have 3 bromo groups at carbon 2 which gives us 2,2,2-tribromoheptanamide.

Finally we have a hydroxy group at carbon 4, so after ordering the substituents alphabetically we get the final answer of 2,2,2-tribromo-4-hydroxyheptanamide.

Now let’s look at the wrong answers:

1) 4-hydroxy-2,2,2-tribromoheptanamide is wrong because according to IUPAC naming conventions the substituents in the name must be named alphabetical order and since B comes before H, 2,2,2-tribromo goes before 4-hydroxy in the name.

2) 6,6,6,-tribromo-4-hydroxyheptan-7-amide is wrong because according to IUPAC naming conventions the highest priority group should have the lowest number, so in this case the amide should be on carbon #1 and have a lower number than the hydroxy group.

3) 4-hydroxy-6,6,6,-tribromoheptan-7-amide is wrong because according to IUPAC naming conventions the highest priority group should have the lowest number, so in this case the amide should be on carbon #1 and have a lower number than the hydroxy group. It is also wrong because according to IUPAC naming conventions the substituents in the name must be named alphabetical order and since B comes before H, bromo goes before hydroxy in the name.

4) 2,2,2-tribromo-4-hydroxyhexanamide is wrong because the longest carbon chain is 7 carbons long, not 6.